G-SYNC 101: Control Panel


G-SYNC Module

The G-SYNC module is a small chip that replaces the display’s standard internal scaler, and contains enough onboard memory to hold and process a single frame at a time.

The module exploits the vertical blanking interval (the span between the previous and next frame scan) to manipulate the display’s internal timings; performing G2G (gray to gray) overdrive calculations to prevent ghosting, and synchronizing the display’s refresh rate to the GPU’s render rate to eliminate tearing, along with the delayed frame delivery and adjoining stutter caused by traditional syncing methods.

G-SYNC Demo

The below Blur Busters Test UFO motion test pattern uses motion interpolation techniques to simulate the seamless framerate transitions G-SYNC provides within the refresh rate, when directly compared to standalone V-SYNC.

G-SYNC Activation

“Enable for full screen mode” (exclusive fullscreen functionality only) will automatically engage when a supported display is connected to the GPU. If G-SYNC behavior is suspect or non-functioning, untick the “Enable G-SYNC, G-SYNC Compatible” box, apply, re-tick, and apply.

Blur Buster's G-SYNC 101: Control Panel

G-SYNC Windowed Mode

“Enable for windowed and full screen mode” allows G-SYNC support for windowed and borderless windowed mode. This option was introduced in a 2015 driver update, and by manipulating the DWM (Desktop Windows Manager) framebuffer, enables G-SYNC’s VRR (variable refresh rate) to synchronize to the focused window’s render rate; unfocused windows remain at the desktop’s fixed refresh rate until focused on.

G-SYNC only functions on one window at a time, and thus any unfocused window that contains moving content will appear to stutter or slow down, a reason why a variety of non-gaming applications (popular web browsers among them) include predefined Nvidia profiles that disable G-SYNC support.

Note: this setting may require a game or system restart after application; the “G-SYNC Indicator” (Nvidia Control Panel > Display > G-SYNC Indicator) can be enabled to verify it is working as intended.

G-SYNC Preferred Refresh Rate

“Highest available” automatically engages when G-SYNC is enabled, and overrides the in-game refresh rate selector (if present), defaulting to the highest supported refresh rate of the display. This is useful for games that don’t include a selector, and ensures the display’s native refresh rate is utilized.

“Application-controlled” adheres to the desktop’s current refresh rate, or defers control to games that contain a refresh rate selector.

Note: this setting only applies to games being run in exclusive fullscreen mode. For games being run in borderless or windowed mode, the desktop dictates the refresh rate.

G-SYNC & V-SYNC

G-SYNC (GPU Synchronization) works on the same principle as double buffer V-SYNC; buffer A begins to render frame A, and upon completion, scans it to the display. Meanwhile, as buffer A finishes scanning its first frame, buffer B begins to render frame B, and upon completion, scans it to the display, repeat.

The primary difference between G-SYNC and V-SYNC is the method in which rendered frames are synchronized. With V-SYNC, the GPU’s render rate is synchronized to the fixed refresh rate of the display. With G-SYNC, the display’s VRR (variable refresh rate) is synchronized to the GPU’s render rate.

Upon its release, G-SYNC’s ability to fall back on fixed refresh rate V-SYNC behavior when exceeding the maximum refresh rate of the display was built-in and non-optional. A 2015 driver update later exposed the option.

This update led to recurring confusion, creating a misconception that G-SYNC and V-SYNC are entirely separate options. However, with G-SYNC enabled, the “Vertical sync” option in the control panel no longer acts as V-SYNC, and actually dictates whether, one, the G-SYNC module compensates for frametime variances output by the system (which prevents tearing at all times. G-SYNC + V-SYNC “Off” disables this behavior; see G-SYNC 101: Range), and two, whether G-SYNC falls back on fixed refresh rate V-SYNC behavior; if V-SYNC is “On,” G-SYNC will revert to V-SYNC behavior above its range, if V-SYNC is “Off,” G-SYNC will disable above its range, and tearing will begin display wide.

Within its range, G-SYNC is the only syncing method active, no matter the V-SYNC “On” or “Off” setting.

Currently, when G-SYNC is enabled, the control panel’s “Vertical sync” entry is automatically engaged to “Use the 3D application setting,” which defers V-SYNC fallback behavior and frametime compensation control to the in-game V-SYNC option. This can be manually overridden by changing the “Vertical sync” entry in the control panel to “Off,” “On,” or “Fast.”



1716 Comments For “G-SYNC 101”

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Joselaba97
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Joselaba97

Just wanted to say thank you for the prolonged work and research you’ve been putting into your findings.

I have some questions and concerns regarding, multi-display configurations utilizing discordanant refresh rates, while one of them being gsync compatible, and also while utilizing DX12 applications with OBS game capture. I’ve also noticed that a good amount of DX12 games have been implementing reflex and other gsync compatibility optimizations as well, so this has expanded the amount of variables to consider for minimal input latency implementations.

For Gears 5, I utilize the NVCP vsync, the internal frame cap system (144 fps), gsync-compatible: full-screen mode only, and the reduced buffering option. However, I’m concerned as to what gsync and vysnc implementation should be used together, specifically the full-screen/full-screen & windowed mode and ON, OFF, Fast, and 3D application setting, respectively. I often stream the game and have noticed a considerable amount of input lag w/ occasional stutters with that concurrent configuration, regardless of the fact that it should be the configuration with the least amount of input lag. I’ve considered that it’s probably due to the secondary 60Hz monitor, but that is essential since it’s utilized to monitor chat and other related tasks while gaming on my 240Hz g-sync compatiable monitor. I also minimize OBS to the system tray in order to ensure that no hardware-accelerated tasks are interfering with the actively rendering game and its respective frame-pacing system.

Also, given that Nvidia has begun implementing optimizations for LLM and gysnc & vsync, is ULLM an option to consider regardless of the RB setting in-game?
Is there something that I have personally overlooked w/ respect to NVCP and the game?
Should I consider using the fixed refresh rate instead? (240Hz, I currently have the NVCP set to Prefer highest refresh rate)
Are there any setting recommendations that you would recommend for my current application? (w/ respect to windows settings, NVCP, and in-game)

Conclusively, gsync has been more of a headache to handle with rather than a “cool” optimization to use in-game. So I ask if you could please provide me with any information regarding my current application and optimization suggestions. Thank you

grumpycalabi314
Member
grumpycalabi314

Hi! First of all thanks for all the work you do. I noticed that if i play Battlefield (4 or 1) and if i set an FPS cap to 138 via NVCP, the game doesn’t feel quite right. I also noticed that the in-game fps counter (perfoverlay.drawfps 1) isn’t really stable (it stays a lot a 139, and jumps even at 141). On the other end, if i set an ingame fps limiter (gametime.maxvariablefps 138), the ingame fps counter is much more stable, always stays at 138 and the game feels much better. Have you done some testing on the frostbite engine to confirm or not this?
PS: VSYNC was set to ON via NVCP
Thanks you for the help.

chron42
Member
chron42

Hi, if I globally set the “Max frame rate” in Nvidia Control Panel to 141 (-3 FPS to my refresh rate), will this introduce the <1 Frame Delay to games where an in-game FPS limiter is available? (Using the in-game limiter I also set the game to max 141 FPS)

Niko
Member
Niko

Hello there, i play destiny 2 a lot and i cant seem to fix this weird stutter i play on a 1080ti and a 8700k oc to 5.0ghz with a 180 hz asus gsync monitor i have all my settings on low and i have gsync enables vsync enabled in nvcp and reflex on in the cvar files, the game just does not feel smooth reflex caps it to about 171 and it just bounces around between 145-171 its super frustrating

NNSLKPTIS
Member
NNSLKPTIS

Hello, sry for my engl. I have a Alienware aw2521hf 240hz and 1070. Usually Im playing Warzone. Please help me with settings for lowest input lag.
NVCP G-sync on
NVCP V-SYNC on.input lag is more lower then off right ?
nvidia reflex on + boost
should I use NVCP low latency mode? because game support nvidia reflex.
and limit maximum refresh rate in game 237 or nvcp 237 ? my fps around 90-110.
Thanks you for the help.

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